Zero waste biorefining of lingonberry (Vaccinium vitis-idaea L.) pomace into functional ingredients by consecutive high pressure and enzyme assisted extractions with green solvents

Abstract

Due to the lack of innovative valorization strategies, berry pomaces are a poorly utilized as a cheap source of valuable nutrients and phytochemicals. An effective biorefining scheme was developed to recover functional components from lingonberry pomace by consecutive supercritical CO₂ (SFE-CO₂), pressurized liquid (PLE) and enzyme assisted (EAE) extractions. SFE-CO₂ at optimized parameters yielded 11.8 g/100 g of lipophilic fraction, containing 43.3 and 37.4% of α-linolenic and linoleic fatty acids, respectively. The combined PLE with ethanol and water additionally recovered 61.8 g/100 g of polar constituents and reduced the antioxidant capacity of starting material by up to 94%. The major portion of the antioxidants (89-94% in different assays), anthocyanins (231 mg/100 g pomace) and proanthocyanidins (15.9 g/100 g pomace) was present in PLE-EtOH extract. Cyanidin-3-galactoside was the major anthocyanin (146.9 mg/100 g). High-pressure fractionation was more efficient for obtaining bioactive pomace constituents as compared with conventional and enzyme-assisted extractions.

Keywords: Anthocyanins; Antioxidant capacity; High-pressure extraction; Lingonberry pomace; Proanthocyanidins.